Patent EA-002768-B1 (EA)
Title: Pyrazolo(3,4-d)pyrimidines with anticonvulsive and antiallergic/antiasthmatic action
Inventor: ARNOLD THOMAS
IPC: A61K31/505
Filed: 1999-06-04
Abstract: 1. New compounds of the general formula 1   or their tautomers, in which  X is oxygen or sulphur and Y is halogen, C1-C4-alkyl, C1-C4-alkoxy, trifluoromethyl or trifluoromethoxy m is 1 or 2, except for 2-benzyl-4,5-dihydro-4-oxo-[3,4-d]pyrimidin 2. Compounds of the general formula 1: 2-(2-fluorobenzyl)pyrazolo[3,4-d]pyrimidin-4(5H)-one 2-(2-chlorobenzyl)pyrazolo[3,4-d]pyrimidin-4(5H)-one  2-(2-bromobenzyl)pyrazolo[3,4-d]pyrimidin-4(5H)-one 2-(2-iodobenzyl)pyrazolo[3,4-d]pyrimidin-4(5H)-one 2-(2-trifluoromethylbenzyl)pyrazolo[3,4-d]pyrimidin-4(5H)-one 2-(2-methylbenzyl)pyrazolo[3,4-d]pyrimidin-4(5H)-one 2-(3-trifluoromethylbenzyl)pyrazolo[3,4-d]pyrimidin-4(5H)-one 2-(2,6-difluorobenzyl)pyrazolo[3,4-d]pyrimidin-4(5H)-one 2-(2-chloro-6-fluorobenzyl)pyrazolo[3,4-d]pyrimidin-4(5H)-one 2-(2,6-dichlorobenzyl)pyrazolo[3,4-d]pyrimidin-4(5H)-one 2-(2,4-dichlorobenzyl)pyrazolo[3,4-d]pyrimidin-4(5H)-one 2-(4-methoxybenzyl)pyrazolo[3,4-d]pyrimidin-4(5H)-one 2-(2-chloro-4,5-methylenedioxybenzyl)pyrazolo[3,4-d]pyrimidin-4(5H)-one 2-(2-chlorobenzyl)pyrazolo[3,4-d]pyrimidine-4(5H)-thione 2-(2-bromobenzyl)pyrazolo[3,4-d]pyrimidine-4(5H) thione 2-(2-iodobenzyl)pyrazolo[3,4-d]pyrimidine-4(5H)-thione 2-(2-trifluoromethylbenzyl)pyrazolo[3,4-d]pyrimidine-4(5H)-thione 2-(2,6-difluorobenzyl)pyrazolo[3,4-d]pyrimidine-4(5H)-thione 3. Process for the preparation of pyrazolo[3,4-d]-pyrimidines of the general formula 1 where X = oxygen, characterized in that a compound of the formula 2   in which Z is hydroxyl, alkoxy or amino and Y is halogen, C1-C4-alkyl, C1-C4-alkoxy, trifluoromethyl or trifluoromethoxy and m is 1 or 2, is cyclized with formamide. 4. Process according to Claim 3 characterized in that alkyl orthoformates or formic acid/acetic anhydride mixtures are used for the cyclization of 3-aminopyrazole-4-carboxamides of the formula 2. 5. Process for the preparation of pyrazolo[3,4-d]-pyrimidines of the general formula 1 where X = sulphur, characterized in that a compound of the formula 1 where X = oxygen is reacted with phosphorus pentasulphide or 2,4-bis(4-methoxy-phenyl)-1,3-dithia-2,4-diphosphetane-2,4-disulphide. 6. Pharmaceutical compositions, characterized in that they contain one or more pyrazolo[3,4-d]-pyrimidines of the formula 1 according to Claim 1 or their pharmaceutically utilizable salts as active compounds in addition to one or more physiologically tolerable auxiliaries and/or excipients and, if appropriate, a diluent. 7. Pharmaceutical compositions, characterized in that they contain one or more pyrazolo[3,4-d]-pyrimidines according to Claim 2 or their pharmaceutically utilizable salts as active compounds in addition to one or more physiologically tolerable auxiliaries and/or excipients and, if appropriate, a diluent. 8. Use of pyrazolo[3,4-d]pyrimidines according to formula 1 for the production of medicaments for the treatment, in particular, of epilepsies of various forms. 9. Use of pyrazolo[3,4-d]pyrimidines according to formula 1 for the production of medicaments for the treatment, in particular, of allergic/asthmatic diseases.